manual postback does not work in asp.net

Question

I am trying to PostBack the Page manually, BUT somehow its not working. I am not sure what i am doing wrong here. I am using Jquery dialog boxes and putting the confirmation box before posting back the page. here is my code.

HTML

 <form id="form1" runat="server">
          <input type="hidden" name="__EVENTTARGET" id="__EVENTTARGET" value="" />
          <input type="hidden" name="__EVENTARGUMENT" id="__EVENTARGUMENT" value="" />

    <asp:CheckBox ID="cbIsCollected" runat="server"  AutoPostBack="false" Checked='<%# MWClickAndCollectHelper.CheckOrderCollectedStatus(AlwaysConvert.ToInt(Eval("OrderId"))) %>'
         OnCheckedChanged="cbIsCollected_CheckedChanged" CssClass="isCollectedCheckBox" />
</form>

JAVASCRIPT

var isCollectedCheckBox = $('.isCollectedCheckBox input[type=checkbox]');

var theForm = document.forms['form1'];
      if (!theForm) {
            theForm = document.form1;
      }
      function __doPostBack(eventTarget, eventArgument) {
            if (!theForm.onsubmit || (theForm.onsubmit() != false)) {
                  theForm.__EVENTTARGET.value = eventTarget;
                  theForm.__EVENTARGUMENT.value = eventArgument;
                  theForm.submit();
            }
      }

$(isCollectedCheckBox).on("change", function () {
                  var checked = this.checked;
                  var checkbox = this;
                  if (checked) {
                  checkbox.checked = true;
                  __doPostBack(checkbox, 'JavaScript');
                 }
                });

CODE-BEHIND

protected void Page_Load(object sender, EventArgs e)
      {
            ClientScript.GetPostBackEventReference(this, string.Empty);

                  string targetCtrl = Page.Request.Params.Get("__EVENTTARGET");
                  postbackId.Text = targetCtrl ?? "First Time Loaded";
                  if (!Page.IsPostBack)
                  {
                        BindGridView(gvOrders, CNCOrderCollection);
                  }
       }

So when I Check the CheckBox it should postback to server and the ControlID name should appear. BUT in my case its always shows 'First time Loaded'. that means page does not recognize it as a postback. I want to raise server side CheckBox_changed event.

Please help.

http://stackoverflow.com/questions/13475428/asp-net-manual-postback-not-working-from-dynamically-created-linkbutton — , Mar 05 '13 at 12:08
shouldn't the call to do __doPostBack be __doPostBack(checkbox.id, 'JavaScript'); ? — jbl, Mar 05 '13 at 12:19
see my edits. i am declaring the variable for that 'isCollectedCheckBox' — patel.milanb, Mar 05 '13 at 12:26
my comment was about the ".id" part which, I think, is missing in your code. — jbl, Mar 05 '13 at 12:46
I dont think its required, still i tried that and its now working. — patel.milanb, Mar 05 '13 at 12:47

jason · Accepted Answer · 2013-03-05T12:30:38.330

Why are you trying to post back "manually"? The checkbox control has a postback handler. Change AutoPostBack to true and set OnCheckedChanged to the name of a event method on the server side. If you want to get the control that sent the click, that's what the sender is for. Example:

<asp:CheckBox ID="cbIsCollected" runat="server"  AutoPostBack="Trye" 
OnCheckedChanged="cbIsCollected_CheckedChanged" CssClass="isCollectedCheckBox" />

Protected Sub cbIsCollected_CheckedChanged(ByVal sender As Object, ByVal e As System.EventArgs)
    dim cbSender as checkbox
    cbSender = ctype(sender, checkbox)

end Sub

If this code isn't accomplishing what you are looking for, let me know.

EDIT:

If you want to do the postback from JS, you have two options. First, you can call the _doPostback like this:

function someFunction()
    {
     __doPostBack('btnName','');
    }

Where btnName is the name of a button on your page.

Second, you can simply have a button on your page that is hidden but has an event handler associated with it. Your client side button click calls calls as JS function that does the click of the server button for you: like this:

function clickButton() {
var getBtn = document.getElementById('<%= btnName.ClientId %>')
getBtn.click()
}

Of course, this seems redundant as why wouldnt the Yes button just have its own event handler and the No button be a client side button that returns false?

I am doing it manually because i am doing some work in Jquery, i am displaying confirmation dialog box to the user if they press yes then its posted back and if they press no then no postback. — patel.milanb, Mar 05 '13 at 12:18
Just call your JS OnClientClick and return false if you don't want the button to postback. — Ben Robinson, Mar 05 '13 at 12:27

manual postback does not work in asp.net

HTML

JAVASCRIPT

CODE-BEHIND

1 Answers1